The present invention relates to a three-dimensional measuring device and a three-dimensional measuring system capable of acquiring many three-dimensional data.
In the past, as a measuring device for acquiring many three-dimensional data (3D data) (three-dimensional point cloud data) of an object to be measured in a short time, a three-dimensional laser scanner has been known.
In a case where a three-dimensional point cloud data is acquired by a three-dimensional laser scanner, a installation position of the three-dimensional laser scanner has to become known. The procedure for measuring the installation position of the three-dimensional laser scanner is as follows. A target is installed at a known position and measured by the three-dimensional laser scanner. Based on the installation position of the target and the measurement result of the target, the installation position of the three-dimensional laser scanner is made known.
In the past, as a method for measuring a target, a target with retroreflective ability (e.g., a reflective sheeting) is employed, and by detecting a reflected light from the target (detecting a light spot), a distance and an angle are measured, and the three-dimensional data of the target are acquired.
Further, in prior arts, in order to detect a target, a distance measuring light has to be scanned over an area in which the target exists. Further, in order to discriminate a retroreflective object from other objects to be measured, an adjustment of a received light quantity and a scanning operation of the distance measuring light have to be performed repeatedly. Therefore, it takes time to detect the target and the measurement of the installation position is inefficient.
JP-A-2010-237169 discloses a method comprising a light spot detection step of projecting a flashing light (pulsed light) toward a target and detecting a light reflected from the target as a light spot, a step of acquiring a moving image of the target and a support unit for the target, a step of detecting the target based on the light spot detection, a step of tracking an image based on the moving image in parallel with the target detection step, a step of comparing a target position obtained by the target detection with an image position obtained by the image tracking, wherein when the target position and the image position are in a predetermined range, the result of the target detection is recognized as the target position and a false recognition is avoided.
Meanwhile, the specification of the U.S. Pat. No. 6,804,380 discloses a method that, in order to measure an arbitrary point such as a tie-point or a subsequent starting point for connecting point cloud data acquired from a plurality of installation positions by a three-dimensional measuring device, a retroreflective region is detected by scanning a distance measuring light over a target sheet with a circular retroreflective region, and a center of the retroreflective region is obtained, and an optical axis of the distance measuring light is aligned with the center of the retroreflective region, and a distance and an angle of the arbitrary point are measured, so a target position is recognized.